Method and apparatus for protecting innerliner of a green tire

ABSTRACT

A method of creating an air barrier on both sides of an innerliner splice on the inside surface of a green tire when a bladder release lubricant is being applied thereto to prevent contamination of the splice. High pressure air is directed through air nozzles on both sides of the innerliner splice just prior to and during the application of the lubricant. A pressure sensor detects high or low air pressure during the creation of the air barriers to stop the spray of lubricant should either situation be detected.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention relates to the manufacture of pneumatic tires and inparticular to an apparatus and system for preventing a bladder releaselubricant, which is sprayed on the innerliner of a green tire, fromcontaminating the innerliner splice. Even more particularly, theinvention relates to the use of high pressure air for forming a barrierabout the innerliner splice to prevent the release lubricant fromcontaminating the splice.

2. Background Information

During the manufacture of pneumatic tires, a green uncured tire istransferred from a tire assembly station to a spray station where abladder release lubricant is sprayed about the interior of the tire ontothe innerliner to prevent the innerliner from sticking to an inflatablebladder at a mold station to which the green tire is subsequentlydelivered. After the green tire has been placed in a curing mold and themold sealed, a bladder is inflated to force the green tire against theheated mold walls whereby the tire is formed with a desired treadpattern. After a curing period, the bladder is deflated and the mold isopened and the cured tire is removed from the mold. However, problemshave been encountered in that the bladder can stick to the innerliner ofthe tire, causing damage to the innerliner and/or bladder upon removalof the tire from the mold.

Therefore, to overcome this sticking problem, the green tire is firstdelivered to a spray station where a release lubricant is applied to theinnerliner of the tire, which is that portion which contacts theexpandable curing bladder. However, this lubricant could affect the tireif allowed to penetrate the innerliner splice which could result in thetire being rejected. Therefore, to avoid this problem, a mechanicalbarrier, such as a flexible fabric, is placed over the innerliner spliceat the spray station to prevent the lubricant from contacting andcontaminating the innerliner splice. However, the use of this mechanicaldevice or covering fabric requires maintenance and increases the cycletime at the spray station.

Therefore, the need exists for an improved method and apparatus which isapplied at the bladder release spray station to prevent thecontamination of the innerliner splice by the sprayed lubricant, whichis effective and which decreases maintenance and improves cycle time ofthe green tire moving through the spray station prior to entering a moldstation.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a method and apparatus which is actuatedand located at a spray station in a tire manufacturing process whichprotects the innerliner splice from contamination by bladder releaselubricant applied to the innerliner of the tire at the spray station.

The method and apparatus of the present invention uses a pair of highpressure air streams directed against the innerliner on opposite sidesof the innerliner splice just prior and during the application of thebladder release lubricant to create an air barrier about the splice toprevent the sprayed lubricant from reaching the splice area.

Another advantage of the invention is to provide a pressure sensorlocated downstream from the pressurized air nozzle which measures forlow and high air pressure, thus detecting loss of air pressure or airnozzle blockage to insure that a required air barrier strength iscreated by the air nozzle. The sensor will cause the lubricant spraynozzles to be deactivated should the pressure sensor detect such high orlow air pressure.

Another feature of the invention is to provide an air pressure nozzlewhich is inserted generally axially into the tire opening and thenlowered into position adjacent the bead area of the tire to form a pairof high pressure air streams which are angled outwardly downwardly fromthe nozzle to opposite ends of the innerliner splice which form the airbarrier until completion of the lubricant spray cycle.

Still another feature of the invention is the ability to mount the airspray nozzle on the existing mechanism used at the spray station forapplying the release lubricant onto the innerliner, thereby avoidingcomplicated and expensive retrofitting of existing spray stationapparatus.

The foregoing advantages, construction and operation of the presentinvention will become more readily apparent from the followingdescription and the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

A preferred embodiment of the invention, illustrative of the best modein which applicant contemplates applying the principles, is set forth inthe following description and is shown in the drawings and isparticularly and distinctly pointed out and set forth in the appendedclaims.

FIG. 1 is a diagrammatic view of a portion of a tire manufacturingprocess in which the improved method and apparatus of the presentinvention is utilized;

FIG. 2 is a side elevational view with portions of a green tire brokenaway and in section, showing the bladder release lubricant being appliedto the innerliner of the tire, with the innerliner splice beingprotected by the air barrier;

FIG. 3 is a diagrammatic sectional view taken on line 3—3, FIG. 2;

FIG. 3A is a view similar to FIG. 3 showing the lubricant spray nozzlesand air nozzle in their lowered operating postition;

FIG. 4 is a fragmentary plan view of the innerliner splice looking inthe direction of arrows 4—4, FIG. 2; and

FIG. 5 is a diagrammatic perspective view of the high pressure airsupply and protection system of the present invention.

Similar numerals refer to similar parts throughout the drawings.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a diagrammatic illustration of a portion of a tiremanufacturing process in which tire components are assembled on a tirebuilding drum 1 to create a green tire indicated generally at 2. Tire 2will have the usual toroidal configuration, and after removal from tirebuilding drum 1 will be moved by a usual tire carrying sling (not shown)or other transfer mechanism, to a spray station indicated generally at3, for applying a bladder release lubricant 6 onto the inner surface orinnerliner 8 of the green tire. Spray station 3 is of a usualconstruction of a type currently used to apply the bladder releaselubricant, in combination with a mechanism for placing a mechanicalcover or flap over an innerliner splice to prevent contamination thereofby the spray lubricant.

As shown in FIG. 3, spray station 3 will include a shaft 10 along whichextends one or more fluid supply lines 12 which connect to a pair oflubricant spray nozzles 14, preferably oriented at 90° from each other,which are attached to shaft 10 by a bracket 15 for rotation within thetire as shown by arrow A in FIG. 2. Thus, when a green tire is movedinto the spray station by a conveyor 16 or other transport mechanism,shaft 10 is moved in the direction of arrow B (FIG. 3) generally axiallyinto the central opening 18 of the tire, defined by bead areas 20. Afterlubricant spray nozzles 14 have completed their spraying cycle as shownby arrow A, FIG. 2, shaft 10 and nozzles 14 are retracted out of theirpositions within tire 2, afterwhich the tire is then moved toward acuring mold 22. Mold 22 contains an inflatable bladder 24 which requiresbladder release lubricant 6 to be applied to the innerliner of the tireto prevent sticking to the bladder after the curing operation has beencompleted. Heretofore, a flexible mechanical flap or cover (not shown)was moved into tire opening 18 by another shaft not shown), and thenlowered radially over the innerliner splice to protect the splice.

However, in accordance with the present invention, this mechanicalprotective shield is replaced by a high pressure air nozzle indicatedgenerally at 28. Air nozzle 28, which could include a pair of nozzles28A and 28B as shown in FIG. 5, is mounted on shaft 10 by a pair ofbearings 26 and support arms 27 extending between bearings 26 and nozzle28. This enables shaft 12 to be rotated to spray the lubricant fromnozzles 14 onto the innerliner while nozzle 28 remains in positionadjacent the innerliner splice. Air nozzle 28 is formed with a pair ofelongated spray orifices 30 which extend generally throughout the lengthof the nozzle so as to extend generally the width of the spacing betweenbead areas 20 of the tire as shown in FIG. 3A. Orifices 30 form a pairof high pressure air streams 32 which extend outwardly downwardly fromthe nozzles so as to extend on opposite ends of an innerliner splice 34(FIG. 4) to protect the splice from the sprayed lubricant from nozzles14. High pressure air streams 32 form a barrier about the splice,preventing the sprayed lubricant from entering the protected areaindicated at 36, which extends about splice 34. At the start of thespraying cycle, shaft 10 extends into the interior of tire 2 above thecentral axis of the tire as shown in FIG. 3, and then lowered radiallyinto its operational position, as shown by arrows D, to a location justabove the open spacing of the tire formed by bead areas 20 as shown inFIG. 3A. After completion of the spray cycle, shaft 10 is raisedradially in the directly of arrow D to the position of FIG. 3 and thenretracted out of opening 18 of tire 2, enabling the tire to be movedalong conveyor 16 to mold station 22.

In further accordance with the invention as shown in FIG. 5, spraynozzle 28 is connected to a high pressure air supply or compressor 38 byair line 40 which extends through a usual pressure regulator 42 whichregulates the pressure of the incoming air. The high pressure air entersnozzle 28 through one or more pressure lines 44. A pressure sensor 46 ismounted downstream from nozzle 28 and is connected thereto by an airline 48. Pressure sensor 46 functions as a detector and detects whetherthe pressure at nozzle 28 is too high or too low with respect to apredetermined limit which indicates a loss of air pressure or blockageof the air nozzle. Should such a pressure change occur it couldadversely affect air streams 32. Thus, sensor 46 will send a signal tothe lubricating fluid supply source, stopping the flow of lubricant tonozzle 14. This insures that a sufficient air barrier is maintainedabout splice 34 whenever spray lubricant 6 is being applied to theinnerliner of the tire.

Although the above discussion refers to the use of high pressure air forcreating air streams 32, it is readily understood that other types offluids could be used without affecting the concept of the invention.Also as indicated above, one or a pair of nozzles are utilized forforming the pair of air streams 32 which creates the desired air barrierabout splice 34, and lubricant spray nozzles 14 can have otherconfigurations than the pair of spaced nozzles as shown in the drawingsand described above.

Accordingly, the improved apparatus and method of the invention enablesa protective shield or barrier to be formed about an innerliner splice,preferably by using inexpensive high pressure air, which protects theinnerliner splice during the spraying of the bladder release lubricantonto the innerliner of the tire at a spray station prior to the tirebeing placed in the curing mold. Furthermore, an air supply safetysystem insures that a sufficiently strong pair of air streams isprovided by nozzle 28 to prevent the penetration of lubricant 6 intoprotected area 36 which extends about innerliner splice 34.

In the foregoing description, certain terms have been used for brevity,clearness, and understanding. No unnecessary limitations are to beimplied therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes and are intended to be broadlyconstrued.

Moreover, the description and illustration of the invention is anexample and the invention is not limited to the exact details shown ordescribed.

1. A method of protecting a splice formed in an innerliner of a green tire from a bladder release lubricant being sprayed on the innerliner of the tire including the steps of: inserting an air nozzle and a lubricant spray nozzle into a central opening of the tire; moving the air nozzle toward the innerliner splice; spraying the lubricant onto the innerliner of the tire; and directing streams of pressurized air towards the splice during the step of spraying the lubricant onto the innerliner to create an air barrier to reduce the amount of sprayed lubricant contacting the splice.
 2. The method defined in claim 1 including the step of sensing the amount of pressure of the pressurized air.
 3. The method defined in claim 2 including the step of stopping the spraying of the bladder release lubricant upon the pressure of the pressurized air dropping below or rising above a predetermined amount.
 4. The method defined in claim 1 including the step of stopping the movement of the air nozzle toward the splice whereby said nozzle is located adjacent a bead area of the green tire.
 5. The method defined in claim 1 including the step of providing the air nozzle with a pair of elongated spray orifices which extend generally between spaced beads of the tire.
 6. The method defined in claim 1 including the step of rotating the lubricant spray nozzle for spraying the lubricant onto the innerliner of the tire.
 7. The method defined in claim 6 including the step of suspending the air nozzle in a fixed non-rotatable position below the lubricant spray nozzles.
 8. A method of protecting a splice formed in an innerliner of a green tire from a bladder release lubricant being sprayed on the innerliner of the tire including the steps of: inserting an air nozzle into a central opening of the tire; moving the air nozzle radially within the tire opening toward the innerliner splice; spraying the lubricant onto the innerliner of the tire; and directing streams of pressurized air towards the sides of the splice during the step of spraying the lubricant onto the innerliner to create an air barrier to reduce the amount of sprayed lubricant contacting the splice.
 9. A method of protecting a splice formed in an innerliner of a green tire from a bladder release lubricant being sprayed on the innerliner of the tire including the steps of: inserting a lubricant spray nozzle generally axially into a central opening of the tire; rotating said lubricant spray nozzle and spraying the lubricant onto the innerliner of the tire; and directing streams of pressurized air against the innerliner of the tire on both sides of the splice during the step of spraying the lubricant onto the innerliner to create an air barrier to reduce the amount of sprayed lubricant contacting the splice. 